I actually finally got it to work! It was a link error that Rider just couldn’t show, for who knows what reason. I ended up opening the workspace in XCode, then in XCode, I tried building and it was failing there, too. I noticed that the build settings were set to something like “MacOS/IOS” so I adjusted all the build settings be “MacOS” only, then I attepted a build inside XCode. This time i get a linker error but i got details! Turns out I was missing “UMG” in my PublicDependencyModuleNames! Added that.
then I built the Editor alone, and that worked. I tried unreal game, that worked, so I moved on to my project code, and the editor build worked, too!
Once I had that going I tried it again in Rider, and it all built and ran the editor with my project!
That was a trip!
AI was nearly useless here, had me going in circles (with small variations) for days!
The key was to build the project in XCode, NOT the terminal.